Abnormal menstruation, often caused by Dysfunctional Uterine Bleeding (DUB), is one of the most common chief complaints to gynecologists and family practices, and is associated with significant morbidity and costs to patients and the healthcare system. First-line treatments include medical management with hormones and other medications and endometrial ablation procedures. Beneficial effects of first line treatments have been well-studied and shown to have few differences when compared past one year. However, a comparative effectiveness approach to adverse events, including endometrial cancer, has not been performed. This is vitally important to patient decision-making and is necessary to establish quality healthcare delivery, given that guidelines for DUB treatment are mixed or absent. Cancer (an AHRQ priority disease) is a pressing outcome for women with DUB because obesity (an AHRQ priority condition) and advancing age (representing the AHRQ priority population of women and the elderly) increases risk for both DUB and endometrial cancer. Objectives and Specific Aims - The overall objective is to optimize the care for DUB by performing a comparative effectiveness study among alternative treatments. The study will have a specific focus on endometrial cancer as the outcome. Specific Aim 1 assesses if endometrial ablation versus medical management carries an increased risk of endometrial cancer. Specific Aim 2 investigates if cancer diagnosis is delayed in women who underwent ablation vs. medical management. Finally, Specific Aim 3 investigates if women who undergo ablation present with a higher surgical stage of endometrial cancer versus those who choose medical management and develop endometrial cancer. Research Design and Methods A retrospective cohort study will be performed in The Health Improvement Network (THIN), a UK medical record database with over 600,000 women with a diagnosis of DUB, who received either endometrial ablation or medical management. The study will report both unadjusted results and results adjusted for possible confounders. It will examine the relative risk of endometrial cancer using Cox proportional hazard models~ it will investigate diagnostic delay by comparing median time from DUB diagnosis to cancer diagnosis between treatment groups~ and it will compare the proportion of stage I endometrial cancers between treatment groups. Impact Results from the study could profoundly influence both treatment paradigms for DUB and screening regimens for endometrial cancer. PUBLIC HEALTH RELEVANCE: The proposed study will compare the effectiveness of endometrial ablation procedures versus management with medications for one of the most common causes of abnormal menstrual bleeding. It is designed to study differences in cancer of the womb (endometrium) by comparing the risk of cancer, the delay in diagnosis of cancer, and the severity of each cancer between these treatment groups. This will help women make informed decisions regarding their treatment options for abnormal menstrual bleeding, and help physicians make proper guidelines and recommendations for cancer monitoring and treatment.